The Greens did spectacularly well in this election (some, in fact, are using the word "greenslide"); they have won a senate seat in each state (annihilating the right-wing religious parties; goodbye national internet firewall), and have also won the lower-house seat of Melbourne, formerly a safe-as-houses Labor seat, with a 10% swing. (Your humble correspondent, a former North Fitzroy resident, has the minor satisfaction of having played a tiny part in this triumph.)
The big question is who is going to get to form the minority government. That's still up in the air (as we speak, several seats are too close to call). If Labor makes it to a strong position, they may be able to count on the Greens to support them (though, if the Greens have been paying attention to the coalition government in the UK, and the Liberal Democrats' spectacular loss of support since going into government with the Tories, they may think twice about coalition with an unpopular party (i.e., either of them)). The Coalition could have an edge at persuading the rural independents that they have rural Australia's interests at heart, though apparently there is little love lost between the ex-Nationals and their old party.
I'd say that a Coalition minority government would be more likely (though by no means certain). And while the prospect of Tony Abbott, a religious authoritarian with a penchant for imposing his own paternalist values through the apparatus of government and the source of much of what was unpalatable about the Howard government, being the next Prime Minister is not an encouraging one (at least to this short-black-drinking inner-city type), one should keep in mind that the government will have to contend with a Senate in which the Greens hold the balance of power. If that is the case, while Labor's positive policies (the National Broadband Network, vague hand-waving about thinking about high-speed rail) may be off the agenda, the Tories are not going to have an easy time of bringing back WorkChoices (which Abbott has ruled out, in the same way that John Howard ruled out a GST in 1995), or turning the government into a hammer of the culture war against the latte-sipping rootless cosmopolitanists (as the Howard government did). And neither party will have to pander to Family First and their ilk.